When 40,000 people died of ergotism (caused by a toxic mould on wheat) in southern France in AD944, nobody would have described it as a 'food scare' (or even une panique alimentaire). The word 'scare', with all its histrionics, is part of a vocabulary of fear developed in the late twentieth century by the healthy, wealthy, comfortable middle classes. It belongs to a world where war, plague and impromptu death have largely been forgotten, where the food we eat - not the absence of food - is perceived as a mass killer.

Every day there is a new danger to worry about (dioxins in salmon, caffeine in pregnancy, beef DNA in chicken). Why are there so many more scares today than there were 20 years ago? First, the steady march towards cut-price food and intensive factory farming have spawned some uniquely modern aberrations (sheep offal fed to cattle, for instance (and, in New Zealand last month, ground-up chicken feathers in the diet of farmed salmon). Second, more fastidious public health initiatives (microbiological testing of food on shelves, routine screening of imported produce) alert us to small theoretical risks based on studies of, say, a 'known' carcinogen in rats. Though there may have been no deaths and the outcome in humans is unproven, a new food scare is born. Meanwhile, the Food Standards Agency (with its remit to protect the public from food) publishes more information daily about the dangers lurking in every fridge.

Finally, in a decade of spin, food scares are rarely left to chance; a plethora of organisations, the news media included, have a vested interest in making the story run and run. A vegan pressure group might commission a study proving all meat is unsafe; an academic institute might receive funding from a charitable trust with an anti-pollution agenda - and the institute may hire a powerful PR company to publicise the convenient 'findings' that intensive farming causes pollution.

Behind every food scare, there is a barrage of claims and counter-claims, hyperbole and damage limitation. How do we pick our way through it? Recently, one study found that civil servants 'especially women' who drank heavily were the least likely to suffer a heart attack. Another, in the same newspaper, warned women about the danger of heart disease as a result of binge drinking. In the end, nobody believes a word of it. That's why, after last month's scare about dioxins and PCBs, salmon sales at supermarkets were largely unaffected. Consumers take it all with a pinch of salt - even if they have read somewhere that salt isn't good for them. Here, then, we publish the truth, our Mutton report.

So are we really at risk?

1. Death by chicken

When? January 2004 The headlines: 'Bird flu could be worse than Sars' (Times); 'EU bans chicken imports from Thailand' (FT).

The story: The H5N1 strain of the virus spread rapidly from Vietnam to Japan, Thailand to China. Experts said that, by latching onto the human flu virus, H5N1 could cause a pandemic of influenza. Within a fortnight, nine people had died from contact with infected birds and millions of chickens had been culled.

The spin: EU banned imports of chicken from Thailand, creating the impression that the meat was unsafe. About 50,000 tonnes of Thai chicken are eaten in UK every year, in the form of frozen or chilled breast meat in ready meals. Curries, nuggets and breaded portions in supermarkets today may contain chicken from Thailand. It's cheap, so popular with school, pub, and hospital caterers.

The facts: As the Food Standards Agency was quick to point out, avian flu has never been known to pass to humans who have eaten infected chicken. It is picked up from live birds, by contact with their saliva, faeces or feathers.

The twist: Bird flu virus can survive freezing and chilling, though infected meat is rendered safe by cooking. However, during an outbreak in the Netherlands last year, farmers put forward a scenario: a piece of thawed, previously frozen raw chicken, infected with the virus, is dumped at a landfill site and carried off by seagulls, infecting a UK poultry flock.

The story: A study in an American journal found farmed salmon to contain 'significantly higher' levels of cancer-causing pollutants than wild salmon.

The spin: Scottish Quality Salmon (SQS) said the findings were 'misleading'; contamination fell well within levels set by the WHO and EU. SQS said the research was 'a deliberately engineered food scare orchestrated to attack the Scottish salmon farming industry'. Stories emerged that it was funded by the Pew Charitable Trust, a research body with an anti-pollution agenda.

The facts: Nobody disputes the figures. What has been contested is the level of risk, since the study uses guidelines on 'safe' chemical intake set by the Environmental Protection Agency. These are hundreds of times more cautious than those of other agencies. By EPA standards, even breast milk would contain 'dangerous' levels of dioxins.

The twist: Farmed salmon sales were up that weekend, probably because the shops drastically reduced the price!

The story: Two studies found that women who drank four cups of coffee a day (300mg of caffeine) were twice as likely to miscarry as those whose intake was low. Mothers who gave birth to small babies were almost twice as likely to have drunk 205mg of caffeine a day as those who had larger babies.

The spin: In 2000, when identical findings were published by a Swedish team, the industry was swift to react. The coffee industry released a statement saying that 240-300mg was a safe intake for pregnant and breast-feeding women; this was based on guidelines drawn up by the independent Centre for Pregnancy Nutrition at the University of Sheffield. 'A cup of instant coffee contains 60mg,' it pointed out, 'which means that five cups a day are within recommended limits.'

The facts: The FSA disagrees. It says an average cup of instant contains 75mg of caffeine, so four cups (or three mugs) is the daily limit. The average cup of brewed coffee contains 100mg, so intake should be no more than three cups - less if you buy the largest size coffee from Starbucks. What's more, tea, cola, and energy drinks contain caffeine.

The twist: For potential fathers, coffee is a good thing. A Brazilian study found that the strength and endurance of sperm is far higher in moderate to heavy coffee drinkers than in those who abstain.

The story: The low-carb/high-fat diet followed by two million Brits came under attack. Dr Susan Jebb of the Medical Research Council's Human Nutrition Research Centre said it would be 'negligent' to recommend it to anyone overweight and many of its claims were 'pseudo science'.

The spin: The pro-Atkins lobby revealed that Dr Jebb was working on a report into obesity, funded by a £20,000 grant from the Flour Advisory Board, who had a vested interest in restoring sales of bread and pasta that had suffered since the Atkins craze.

The facts: British Nutrition Foundation and the British Dietetic Association also oppose the Atkins Diet on health grounds. The FSA warned: 'Healthy eating is about maintaining a balance and that means fruit and veg, bread and cereals and less salt, sugar and fat.'

The twist: In January, Atkins Nutritionals (behind the Atkins diet) warned that only 20 per cent of a dieter's calories should come from saturated fat. While welcomed by health experts, it was a blow for those who had eaten steak and a full English breakfast with impunity.

5. Are your child's chicken nuggets dangerous?

When? May 2003 The headlines: 'Scandal of beef waste in chicken' (Guardian).

The story: A BBC Panorama team, working with the Guardian, filmed Dutch and German food workers boasting about ways of injecting chicken with beef protein without being detected. The protein absorbs water, adding bulk cheaply. Chicken nuggets from Sainsbury's were shown to contain pork and bovine DNA.

The spin: Pre-publicity for the BBC film predicted 'a major food scandal'.

The facts: Despite the BBC's findings (including 'several' samples out of 12 testing positive for beef DNA), the FSA has found only one. Sainsbury's said the beef DNA in its nuggets came from milk protein, shown as an ingredient on the label; in its own tests it found no pork DNA in any sample, and concluded that the Panorama chicken must have been contaminated in the lab.

The twist: If the Dutch producers can now conceal beef adulteration from the authorities, it wouldn't show up on the DNA tests, would it?

6. Swordfish can give you mercury poisoning!

When? May 2002 The headlines: 'Predatory fish health warning' (BBC).

The story: The FSA advised that pregnant women, those wishing to become pregnant and children under 16 should avoid these fish due to high levels of methylmercury found in their flesh.

The spin: British shoppers rushed to health websites to find out about mercury poisoning. 'Mercury is known to be neurotoxic to humans,' reads one entry. 'It can harm the nervous system of an unborn child. Children may be at greater risk because they eat more food relative to body size.'

The facts: Being high in the food chain (and consuming other fish), the large deep sea species do absorb more mercury - a byproduct of industry - than others. They also live longer, absorbing more pollutants.

The twist: Exactly one year after the ban, a study appeared in The Lancet, saying that pregnant women had little to worry about. Research conducted on mothers and children in the Seychelles, who eat 12 fish meals per week, found no evidence of abnormalities.

A further twist: The FSA still advises pregnant women, breast-feeding mothers and children not to eat swordfish, marlin and shark. Indeed, its advice has been extended to include tuna (no more than two cans or one fresh tuna steak per week).

7. Prawns could give you cancer

When? March 2002 The headlines: 'Natural prawn killers' (Sun).

The story: Warm-water prawns from Asia were withdrawn from supermarkets amid fears about the illegal drug nitrofurans - used to kill micro-organisms in overcrowded shrimp farms and believed to cause cancer in humans. Nine UK retailers, including Sainsbury's, Tesco, Safeway, Iceland and the Co-op were asked to remove suspect batches from their shelves. Sales of tiger prawns fell.

The spin: The news was yet more ammunition for the Environmental Justice Foundation (EJF), opposed to the intensive farming of prawns. In June 2003, it launched a campaign based on its report 'Smash and Grab', a damning exposé of the industry. It made headline news.

The facts: In tests conducted by the FSA in March 2002, 16 out of 77 samples tested contained nitrofurans.

The twist: No one died and the scare was quickly forgotten. However, the EJF campaign stuck in people's minds. Most people know there is problem with prawns but few can remember what it is!

The story: In 1980, a Czech scientist was studying Hydrolised Vegetable Protein, a food additive used in Soviet bloc countries; it was found to contain 3-MCPD, a chemical later linked to cancer in rats. HVP is also used by unscrupulous manufacturers to boost flavour in soy sauce. In random tests, 22 out of 100 soy sauces on shelves in Britain contained more than the EU's permitted amount of 3-MCPD. The public was advised to avoid suspect brands, such as Golden Mountain from Thailand.

The spin: The Daily Express headline sparked major panic, suggesting that all Chinese food was toxic, when only soy sauce was under investigation.

The facts: Soy sauce made the traditional way is safe (as the longevity of the Chinese shows). Massive consumption of 'fake' soy would have to take place to increase the risk. No human deaths have been linked to 3-MCPD.

The twist: Foods such as bread, burgers, bacon, savoury crackers and salami contain 3-MCPD. However, no limits have been drawn up for any produce other than soy sauce and, with other foods, it is hard to say where the carcinogenic chemical came from. So soy has been sorted. With other foodstuffs, who knows?

9. Coca-cola is banned!

When? June 1999 The headlines: 'Coke is banned after safety scare' (Guardian).

The story: Coca-cola withdrew 30m cans and bottles from sale in Belgium after nearly 100 people suffered attacks of nausea and stomach cramps. Bans followed in France, Luxembourg and Holland. The company reassured consumers that UK consignments were untainted, but fears remained that small retailers may have bought cases of Coke on the Continent where it was cheaper.

The spin: A statement was issued, saying the gas used to carbonate drinks in Antwerp had been 'of bad quality'. In Dunkirk, lacquered cans had absorbed some spilled pesticide which the victims may have inhaled.

The facts: Chemical analysis had found nothing wrong with the drinks and executives were struggling to find an explanation.

The twist: In early July, a letter appeared in The Lancet signed by four Belgian academics. They believed the Coke episode had been an outbreak of mass hysteria, triggered by another, more serious food scare involving dioxins in meat and poultry, a scandal that brought down the Belgian government. In the highly-charged atmosphere and media frenzy, people had fallen ill because they believed they would. There may have been hydrogen sulphide in bottles, imparting an odd smell, but the illness 'was in their minds'.

The story: Food poisoning outbreak in Lanarkshire, Scotland, killed 16 people in a month. Final death toll was 20, mostly aged over 60. Health authorities traced the bacterial infection E.coli 0157 to a butcher's shop selling cooked meat pies.

The spin: Not much, but note that the Sun described it as 'a small award-winning butcher's shop'.

The facts: E.coli affects fewer people than other major food-poisoning bugs (campylobacter and salmonella) and accounts for 1,100 cases a year in UK. Symptoms range from vomiting and diarrhoea to kidney failure and death in children and the elderly.

The twist: In January 2002, a study found E.coli 0157 in organic lettuce. The bacterium, which multiplies in the gut of cattle, is present in the manure used as organic fertiliser. From there, it can spread through the lettuce's root system to the edible part of the plant.

11. Perrier - it's lethal!

When? February 1990 The headlines: 'Perrier expands North American recall to rest of globe' (Wall Street Journal).

The story: In North Carolina, bottles of Perrier were found to be contaminated with benzene, a poisonous liquid shown to cause cancer in lab animals. The company withdrew 70 million bottles from sale in the US and Canada, the start of a well-charted PR disaster.

The spin: Initially, Perrier claimed the problem was unique to the US, caused by an employee cleaning machinery with a fluid containing benzene. When contaminated bottles showed up in Denmark and the Netherlands (bringing the total to 13), the story changed: benzene, the spin doctors now said, was naturally present in carbon dioxide (the gas that makes Perrier bubbly) but filtered out. The real problem had been a blocked filter. Amid growing consumer mistrust, a further 90 million bottles were withdrawn globally at an estimated loss of $263million.

The facts: The contamination level of 22 parts per billion did not pose 'a significant short-term health risk', according to the US Food and Drug Administration, but the company acted to protect its brand, which was marketed on purity.

The twist: The plan backfired. Investigators found that Perrier was not 'Naturally Sparkling', but carbonated above ground. By 1995, sales had dropped to half their 1989 peak.

12. Baby killer cheese bug!

When? March 1989 The headlines: 'Baby killer cheese bug' (Sun).

The story: Screening of imported pté found high levels of listeria monocytogenes, linked to miscarriage, stillbirth and meningitis in babies of infected mothers. Pregnant women were told to avoid pté and soft-ripened cheeses (Brie, Camembert, Danish blue, Gorgonzola and Stilton). Sales of cheese, including cottage cheese, cream cheese and fromage fraîs, plummeted.

The spin: Continental Europeans rubbished the idea, saying that generations of French and Italian women and children had eaten soft cheese without ill effect.

The facts: Between 1987 and 1989, 26 babies in the UK died from listeriosis. The total number of deaths rose to 250 from closer to 100 in a typical year. The increase was ascribed to a new, aggressive subtype of L.monocytogenes present in the pté sampled and in raw, unpasteurised milk. The low temperatures at which the curd for soft cheese is cooked will not kill L.monocytogenes , while low acidity and high moisture levels allow it to thrive. However, hard cheeses are not affected and no health warning was ever issued about cottage cheese, cream cheese or fromage fraîs.

The twist: In 1992, an outbreak in France killed 63 people and resulted in 22 abortions. In 1995, 17 fell ill (again in France) after eating Brie de Meaux, including nine pregnant women: there were two stillbirths and two abortions. Britain introduced new food-hygiene regulations and cases of listeria dropped dramatically. In January this year, one-fifth of smoked salmon samples bought in UK supermarkets were found to contain listeria.

The story: Health minister Edwina Currie provoked outrage by claiming: 'Most of the egg production in this country, is now affected with salmonella.' Everybody stopped eating eggs, the industry faced bankruptcy and farmers demanded compensation. Two weeks later Currie was forced to resign.

The spin: The Ministry of Agriculture said eggs were fine, as long as they were cooked until solid.

The facts: In Britain, there are 4,000 cases every year of infection from salmonella DT104, the most dangerous strain of the food bug, of whom about three per cent die. Though eggs destroyed Currie, the most common source of infection is meat. In 2000, the Government reported that 23 per cent of pigs taken for slaughter are infected.

The twist: A study conducted months after Currie's 'gaffe' proved she was nearly right on all her findings.

14. Burger with extra BSE!

When? November 1986 The headlines: At this stage, unbelievably, there weren't any.

The story: In the late Eighties/early Nineties, 100,000 cattle were diagnosed as having BSE, the result of feeding meat by-products to herbivores. In 1996, beef exports to Europe were banned.

The spin: In a flawed PR stunt John Gummer, then Minister of Agriculture, said beef was 'completely safe'. He appeared on TV with his four year-old daughter, and encouraged her to bite into a burger.

The facts: In 1995, Stephen Churchill, 19, became the first person to die from vCJD, the human variant of BSE (death toll today is 100). In 1996, the Government admitted a 'probable link' between the two.

The twist: Last July, a survey showed that red meat consumption was back to pre-BSE levels.